<rdar://problem/10542095> Focus rings are not drawn around push buttons, radio button...

<rdar://problem/10542095> Focus rings are not drawn around push buttons, radio buttons and checkboxes

Reviewed by Darin Adler.

Instead of relying on -setShowsFirstResponder: to make -drawWithFrame:inView: draw the focus
ring, use -drawFocusRingMaskWithFrame:inView:.

* platform/mac/ThemeMac.mm:
(-[NSCell _web_drawFocusRingWithFrame:inView:]): Added. Sets up the focus ring style and a
transparency layer, then uses -drawFocusRingMaskWithFrame:inView: to draw the focus ring.
(WebCore::updateStates): Eliminated calls to get and set showsFirstResponder.
(WebCore::paintCheckbox): Changed to use -_web_drawFocusRingWithFrame:inView:.
(WebCore::paintRadio): Ditto.
(WebCore::paintButton): Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@102246 268f45cc-cd09-0410-ab3c-d52691b4dbfc